The Curse of the Bambino was a superstition cited as a reason for the failure of the Boston Red Sox baseball team to win the World Series in the 86-year period from 1918 to 2004. While some fans took the curse seriously, most used the expression in a tongue-in-cheek manner.
The curse was said to have begun after the Red Sox sold Babe Ruth, sometimes called The Bambino, to the New York Yankees in the off-season of 1919-1920. Before that point, the Red Sox had been one of the most successful professional baseball franchises, winning the first World Series and amassing five World Series titles. After the sale they went without a title for decades, as the previously lackluster Yankees became one of the most successful franchises in North American professional sports.

The "Curse of the Bambino" is an excuse that the Red Sox use because they don't wanna admit they just suck